Greenland registers a colossal glacial flood

Dec. 13 () –

For the first time, the release of a huge outburst from a glacial lake in eastern Greenland has been observed, where three billion liters of water were released in a few weeks this fall.

This rare natural flooding event, witnessed by researchers at the University of Copenhagen, is equivalent to a huge mountaintop bathtub filled with water – equivalent to three times Denmark’s annual water consumption – suddenly overflowing. This is basically what happened when the massive Catalina Lake in eastern Greenland released 3.4 cubic kilometers of meltwater (3 trillion liters) into Scoresby Sound Fjord.

The enormous volume places this event among the three largest of its kind ever documented. Flooding due to meltwater overflow occurred between September 23 and October 11, during which the lake’s water level plummeted 154 meters. The spectacular phenomenon was observed for the first time in real time with satellite images by scientists from the Niels Bohr Institute at the University of Copenhagen.

“We had already found traces of similar flash floods, but due to the polar night and clouds that prevent satellite observations, this is the first time that researchers have been able to monitor an event and measure water volumes in real time,” he explains. in a statement Niels Bohr Institute climate researcher Aslak Grinsted.

The flash flood in East Greenland occurred because meltwater from Lake Catalina had been accumulating over the past twenty years. The lake is situated in a valley blocked by the massive Edward Bailey Glacier. As the lake filled, the water began to lift the glacier, digging a 25 kilometer long tunnel under the ice, through which the water eventually burst into the world’s largest fjord, Scoresby Strait.

This phenomenon, in which a glacial lake gradually fills and then releases its water in a flash flood, is known as a glacial lake flash flood (GLOF). These events have become increasingly frequent over the past three decades due to rising global temperatures and climate change.

“The danger of glacier-dammed lakes is increasing due to global warming. It is vital to improve our understanding of this phenomenon to issue timely warnings in case there is an imminent risk,” says Grinsted.

While glacial lake flash floods can be catastrophic in populated areas like the Himalayas, where they often destroy villages, this particular flood caused no damage due to Greenland’s sparse population. However, a 2023 study concluded that 15 million people around the world live under the threat of deadly glacial floods.

“I think that in the coming centuries, as the Greenland ice sheet melts, we will see even larger lake eruptions. At the end of the last Ice Age, Lake Missoula suffered an eruption that was 2,500 times larger than the recent Catalina eruption. To understand these massive forces, we must study the largest eruptions when they occur,” says Aslak Grinsted.

The energy released by glacial lake floods is astonishing. “In this case, the energy released by the flooding of a glacier was equivalent to the output of the world’s largest nuclear power plant running at full capacity for 22 days“explains Aslak Grinsted.

According to the researcher, it is worth considering how to harness the immense energy of these natural phenomena as a source of green energy. In theory, the energy released by the Lake Catalina event could have continuously provided 50 megawatts of electricity, enough to meet the needs of a small city.

However, in this case, The nearest settlement is 180 kilometers away and is inhabited by just 350 residents.which poses a significant technological challenge for energy use.

“As with many other natural resources in Greenland, infrastructure is a problem. But if a brilliant engineer could figure out how to harness these meltwater outbreaks, there would be enormous energy potential in them,” concludes Grinsted.